Proteinaceous materials coupled to one or more cosmetic care benefit agents have been reported in the art. Lang et al. in U.S. Pat. No. 5,192,332 describe temporary coloring compositions that contain an animal or vegetable protein, or hydrolysate thereof, which contain residues of dye molecules (e.g., benefit agents) grafted onto the protein chain. In the Lang et al. compositions, the protein serves as a conditioning agent and does not provided targeted delivery or enhanced durability for coupling the benefit agent to the target surface.
Proteinaceous materials having strong affinity for a body surface have been used for targeted delivery of one or more personal care benefit agents. However, many of the materials used for targeted delivery are comprised or derived from immunoglobulins or immunoglobulin fragments (antibodies, antibody fragments, Fab, single-chain variable fragments (scFv), and Camelidae VHH) having affinity for the target surface. For example, Horikoshi et al. in JP 08104614 and Igarashi et al. in U.S. Pat. No. 5,597,386 describe hair coloring agents that consist of an anti-keratin antibody covalently attached to a dye or pigment. The antibody binds to the hair, thereby enhancing the binding of the hair coloring agent to the hair. Similarly, Kizawa et al. in JP 09003100 describe an antibody that recognizes the surface layer of hair and its use to treat hair. A hair coloring agent consisting of the anti-hair antibody coupled to colored latex particles is also described. The use of antibodies to enhance the binding of dyes to the hair is effective in increasing the durability of the hair coloring, but the antibodies are difficult and expensive to produce. Terada et al. in JP 2002363026 describe the use of conjugates consisting of single-chain antibodies, preferably anti-keratin, coupled to dyes, ligands, and cosmetic agents for skin and hair care compositions. Although single-chain antibodies may be prepared using genetic engineering techniques, these molecules are expensive to prepare and may not be suitable for use in commercial personal care products due to their conserved structure (i.e., immunoglobulin folds) and large size.
Non-immunoglobulin derived scaffold proteins have also been developed for targeted delivery of benefit agents to a target surface, such as delivery of cosmetic agents to keratin-containing materials (See Binz, H. et al. (2005) Nature Biotechnology 23, 1257-1268 for a review of various proteins used in scaffold-assisted binding). Findlay in WO 00/048558 describes the use of calycin-like scaffold proteins, such as β-lactoglobulin, which contain a binding domain for a cosmetic agent and another binding domain that binds to at least a part of the surface of a hair fiber or skin surface, for conditioners, dyes, and perfumes. Houtzager et a. in WO 03/050283 and US 2006/0140889 also describe affinity proteins having a defined core scaffold structure for controlled application of cosmetic substances. As with immunoglobulin-like proteins, these large scaffold proteins are somewhat limited by the requirement to maintain the underlying core structure for effective binding and are expensive to produce.
Short, single chain peptides (i.e., “target surface-binding peptides”) having strong affinity for a target surface can be identified and isolated from peptide libraries using any number of biopanning techniques well known to those skilled in the art including, but not limited to bacterial display, yeast display, combinatorial solid phase peptide synthesis, phage display, ribosome display, and mRNA display technology (PROFUSION™, U.S. Pat. No. 6,258,558. Techniques to generate random peptide libraries are described in Dani, M., J. of Receptor & Signal Transduction Res., 21(4):447-468 (2001). Phage display libraries are available commercially from companies such as New England BioLabs (Beverly, Mass.).
The target surface-binding peptides are typically no more than 60 amino acids in length and often have a binding affinity (as measured by an MB50 or KD value) of 10−4 M or less for the target surface. These short peptides may be used in some applications as an interfacial material to couple one or more benefit agents to the target surface. However, for some commercial applications the individual biopanned peptides (herein referred to as providing a “monovalent” interaction) may not provide the durability necessary to achieve the desired effect. The lack in durability may be especially evident when attempting to couple a particulate benefit agent to the target surface.
Single chain peptide-based reagents lacking a scaffold support or immunoglobulin fold have been developed that can be used to couple benefit agents to a target surface. Examples of target surfaces include, but not are limited to body surfaces such as hair, skin, nail, and teeth (U.S. Pat. Nos. 7,220,405; 7,309,482; and 7,285,264; U.S. Patent Application Publication Nos. 2005-0226839; 2007-0196305; 2006-0199206; 2007-0065387; 2008-0107614; 2007-0110686; and 2006-0073111; and published PCT applications WO2008/054746; WO2004/048399; and WO2008/073368) as well as other surfaces such as pigments and miscellaneous print media (U.S. Patent Application Publication No. 2005-0054752), and various polymers such as polymethylmethacrylate (U.S. Patent Application Publication No. 2007-0265431), polypropylene (U.S. Patent Application Publication No. 2007-0264720), nylon (U.S. Patent Application Publication Nos. 2007-0141629 and 2003-0185870), polytetrafluoroethylene (U.S. patent application Ser. No. 11/607,734), polyethylene (U.S. Patent Application Publication No. 2007-0141628), and polystyrene (U.S. Patent Application Publication No. 2007-0261775). However, some single chain peptide-based reagents may lack the durability required for certain commercial applications, especially when coupling a particulate benefit agent to a body surface in a highly stringent matrix.
Single chain target surface-binding domains (herein referred to as “hands”) may be prepared by linking together a plurality of target surface-binding peptides (herein referred to as “fingers”). However, due to the absence of a scaffold or core structure to help control the translational and rotational entropies lost in binding between ligands (e.g., the target surface-binding peptides) and the associated polyvalent receptor (i.e., the target surface, such as a body surface), many single chain target surface-binding domains that are unstructured in solution do not exhibit polyvalent interactions. As such, rationally-designing single chain peptide reagents is often difficult. This is particularly true when attempting to design single chain peptide reagents having affinity for a target surface that is heterogeneous in nature and/or wherein the binding motifs may not be well characterized. As such, rationally-designing target surface binding domains capable of effectively forming (or promoting the formation of) multivalent associations from singe chain target surface-binding peptides remains a problem to be addressed for certain commercial applications. This is especially true for single chain target surface-binding domains lacking a conserved scaffold support, as the entropy associated with the unstructured system may adversely impact the formation of stable multivalent interactions.
Mammen et al., (Angew. Chem. Int. Ed. (1998) 37:2754-2794) examines and reviews the theoretical considerations of polyvalent interactions in biological systems and the central role entropy plays in polyvalency. Polyvalent interactions can be collectively much stronger than corresponding monovalent interactions. The increase in affinity observed with multivalent binding vs. monovalent binding is mostly attributed to decreases in the rate of dissociation (Koff) rather than an increase in the rate of association (Kon). Mammen et al. provides examples of biological systems involving polyvalent interactions including, but not limited to ligand-receptor interactions between bacterium and host cell matrices, antibody-antigen interactions, virus and host cell receptors, and signal transduction interactions, to name a few.
The entropy of a polyvalent interaction is a combination of the translational and rotational entropies (Mammen et al., J. Org. Chem. (1998) 63:3168-3175 and Mammen et al., J. Org. Chem. (1998) 63:3821-3830). Due to the absence of a scaffold or core structure to help control the translational and rotational entropies present between ligands (e.g., the target surface-binding peptides) and the associated polyvalent receptor (i.e., the target surface, such as a body surface), single chain target surface-binding domains and/or single peptide-based reagents may not exhibit multivalent binding behavior.
One problem to be solved is to provide single chain peptide-based reagents comprising one or more single chain target surface-binding domains exhibiting strong binding affinity for the target surface.
Another problem to be solved is to provide a method of identifying single chain target surface-binding domains having strong affinity for a target surface. Preferably the method provides target surface-binding domains that exhibit multivalent binding characteristics for the target surface.
A method of coupling a benefit agent to a target surface using a single chain peptide-based reagent comprising at least one target surface-binding domain exhibiting strong affinity for the target surface is also needed.